[Hypotension following a one-time (initial) dose of captopril]

In a group of 269 untreated hypertensive patients the effect of a single oral dose of captopril (25 mg) on blood pressure was studied for 90-120 minutes. The systolic blood pressure decreased by more than 20% in 9.5% and by more than 30% in 1.1% of the patients. In 22.6% the diastolic blood pressure decreased by more than 20%; in 4.5% it fell more than 30%. The calculated mean arterial pressure (MAP) was reduced by more than 20% in 12.3% of the patients and by more than 30% in 3%. Three patients showed transient neurological deficits. Factors related to a strong blood pressure drop were: renal artery disease and resistant hypertension. However, a potentially dangerous fall in blood pressure, i.e. an acute fall of MAP of over 30%, was also observed in the absence of these risk factors. Therefore not all patients at risk can be identified in advance, and treatment with ACE-inhibitors has to be started under well-controlled circumstances especially in elderly patients.